The fib locus in Streptococcus pneumoniae is required for peptidoglycan crosslinking and PBP-mediated beta-lactam resistance

FEMS Microbiol Lett. 2000 Jul 1;188(1):81-5. doi: 10.1111/j.1574-6968.2000.tb09172.x.


Penicillin resistance in pneumococci is mediated by modified penicillin-binding proteins (PBPs) that have decreased affinity to beta-lactams. In high-level penicillin-resistant transformants of the laboratory strain Streptococcus pneumoniae R6 containing various combinations of low-affinity PBPs, disruption of the fib locus results in a collapse of PBP-mediated resistance. In addition, crosslinked muropeptides are highly reduced. The fib operon consists of two genes, fibA and fibB, homologous to Staphylococcus aureus femA/B which are also required for expression of methicillin resistance in this organism. FibA and FibB belong to a family of proteins of Gram-positive bacteria involved in the formation of interpeptide bridges, thus representing interesting new targets for antimicrobial compounds for this group of pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Carrier Proteins / metabolism*
  • Chromatography, High Pressure Liquid
  • Hexosyltransferases*
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Muramoylpentapeptide Carboxypeptidase / metabolism*
  • Mutagenesis, Insertional
  • Operon*
  • Penicillin-Binding Proteins
  • Peptidoglycan / chemistry
  • Peptidoglycan / metabolism*
  • Peptidyl Transferases*
  • Sequence Analysis, DNA
  • Streptococcus pneumoniae / drug effects
  • Streptococcus pneumoniae / genetics*
  • Streptococcus pneumoniae / metabolism
  • beta-Lactam Resistance / genetics*
  • beta-Lactams / pharmacology


  • Bacterial Proteins
  • Carrier Proteins
  • FemA protein, Bacteria
  • FemB protein, Staphylococcus epidermidis
  • FibA protein, Streptococcus pneumoniae
  • FibB protein, Streptococcus pneumoniae
  • Penicillin-Binding Proteins
  • Peptidoglycan
  • beta-Lactams
  • Peptidyl Transferases
  • Hexosyltransferases
  • Muramoylpentapeptide Carboxypeptidase

Associated data

  • GENBANK/AJ277484
  • GENBANK/AJ277485